Canine eosinophilic granuloma of the digits treated with prednisolone and chlorambucil.

BACKGROUND: Canine eosinophilic granuloma (CEG) is an uncommon disease. Lesions are typically located in the oral cavity and other cutaneous sites, but are rarely reported to affect the digits. The majority of cases are treated with prednisolone as a monotherapy; alternative treatment options include corticosteroids administered in combination with azathioprine, antihistamines, electrochemotherapy with bleomycin, and surgical resection. Neither chlorambucil nor laser previously have been reported as treatments.

OBJECTIVES: To describe an alternative therapy for treatment of CEG; using chlorambucil in combination with prednisolone for those cases that fail to respond to prednisolone alone. The new treatment was chosen according to good clinical practice and after owner consent.

ANIMALS: Two client owned dogs.

METHODS: One case was initially treated with carbon dioxide laser to debulk the lesions. Both cases were treated with a combination of oral prednisolone and chlorambucil.

RESULTS: Both dogs experienced rapid resolution of lesions with prednisolone and chlorambucil therapy. Case 1 remained in remission three months after withdrawing medication. Case 2 experienced relapse 10 weeks after discontinuing therapy but was well controlled on maintenance prednisolone with chlorambucil at low, well tolerated doses.

CONCLUSIONS AND CLINICAL IMPORTANCE: Although CEG appears to be an uncommon disease, it should be included as a differential diagnosis for dermal, nodular lesions affecting the digits. Chlorambucil appears to be an effective and well tolerated prednisolone sparing agent for treatment of CEG. Carbon dioxide laser ablation appears to be an effective method of debulking CEGs.